A floor sink is a plumbing fixture that is installed in the floor of a structure which is mainly designed to remove any standing water near it. Floor sinks are typically installed in commercial basements, restrooms, kitchens, refrigerator areas, locker/shower rooms, laundry facilities, and near swimming pools. The sinks are typically round or square-shaped. A strainer or grate is typically secured over the floor sink to prevent injury or entry of foreign objects. Depending on the application, a floor sink may be provided with a whole grate, a one-half grate, or a three-quarter grate. For the partial grates, the remaining area of the drain is provided with a solid cover. As a result, standard floor sink designs require stocking of many different sizes of grates and covers to accommodate all of the variations. Accordingly, there is a need for a modular design for a floor sink frame and grate assembly.